Non-detachable, easy open metallic can ends are routinely employed in the packaging of beer and soft drinks in metal cans. A representative can end forming machine is disclosed, for example, in U.S. Pat. application Ser. No. 07/104,745, filed Oct. 5, 1987, entitled "Method And Apparatus For Forming Can Ends", assigned to the assignee of the present invention. In such apparatus, ends are blanked from sheet material and formed in a die set. Pull tabs of the type disclosed in U.S. Pat. No. 3,967,752 issued July 6, 1976 assigned to Reynolds Metals Company, are then formed in the can end. The pull tabs may be of the stay-on tab style, as aforementioned, or may be the throw-away tab style, or the complete panel removal style and other styles. In all instances, there should be some resistance to moving the pull tab to form the opening in the container lid but not so much resistance that the opening is too hard to form, or cannot be formed, or too little resistance that the container lid will prematurely open. To ensure customer satisfaction in the forming of openings of container lids, it is practice to test samples of these container lids to ensure that the can end manufacturing apparatus for making the container lids is functioning properly. One such testing apparatus with which the present invention may be employed is disclosed in U.S. Pat. No. 4,850,230, issued July 25, 1989 to Adolph Coors Company, Golden, Colorado, and entitled "Pull Tab Force Measuring Apparatus."
The foregoing can end tester is traditionally used in a can end manufacturing plant wherein numerous can end forming machines are in continuous operation under the supervision, during any particular shift, of different quality control plant technicians or operators who monitor their particular forming machines. One of the responsibilities of these operators is to periodically remove a sample set of can ends from every package or "sleeve" of approximately 480 ends being manufactured. Alternatively, the samples could come from the production line prior to packaging (i.e., real time testing). This sample set is brought by the operator or technician and inserted into the system infeed hopper of the can end tester. The operator/technician will then provide the following information to the can end tester via keyboard input: the operator's clock number (i.e., identifier); the machine number from where the samples were taken; the type of inspection (e.g., opening or tab strength); and the current shift. When the operator/technician is finished, he or she will then return to their normal duties while automated testing occurs.
Since numerous technicians (responsible for different can end forming machines) will be delivering sample ends to the can end tester as part of their normal duties, a backlog is frequently created and it is customary for the technician to place his stack or set of sample ends in the feeder magazine on top of the stack of ends that were already logged in by a different technician. In the prior art, the technician would physically place the ends in the hopper. As each end was fed into the bail assembly during the test cycle, it would be sprayed with a serial number with an ink jet printer. However, there was no means available to the operator to identify a sequential printed number prior to the test nor was there a means to separate the sample sets in the computer generated data. Therefore, the technician could not leave the testing machine unless he somehow marked the leading or trailing can ends in the set and later retrieved these ends in the passed and failed ends bins. Such an end count method of coordinating data to samples was time consuming and subject to data confusion.